This invention relates to tube bases and more particularly to tube bases for cathode ray tubes which employ high voltage differentials between various tube pins.
Current and projected types of cathode ray tubes, particularly those employed in color television, have a small diameter neck containing the electron gun or guns. The necessary operating voltage for the various elements of these guns (heaters, cathodes, grids, focusing electrodes, etc.) are supplied via tube pins which are sealed into the end of the tube. As more efficient guns have developed, the neck diameter of these tubes has gotten smaller, thus dictating that the tube pins, which are annularly arrayed thereabout, keep getting closer together.
Prior art tubes have always had large voltage differentials, sometimes on the order of 5 KV to 8 KV. These high voltage connections have usually had some form of arc protection incorporated into the female socket, see, for example, U.S. Pat. Nos. 3,466,491 and 3,466,492. Such protection, however, has proven incapable of providing adequate protection for the newer tube types.
Another method previously employed, in conjunction with a base, was for an operator to individually dispense a fluid silicone about a high voltage lead, e.g., the focus lead. This process was troublesome because it took a long time for the silicone to cure. Further, dispensing the silicone by hand could cause bubbles or air pockets to form therein thus contributing to arcing problems. And, of course, an operator was required, thus adding an undesired cost to the tube.